More of a rambler than a climber. Steady repeat bloomer. Minimal fragrance. Quite possibly the best of the Explorer series to come out of the Canadian breeding program due to it's excellent disease resistance and repeat blooms. These sentences are from my vines class course book at Longwood. Don't grow myself. On display at Longwood Gardens trained on an arbor, in the rose garden area.

William Baffin did well for me the first few years I had it, as you can see in the following photo:
It has since gotten leggy and woody, and doesn't bloom much these days. That could be due to the fact that it gets less sun now than it did then.

You might want to consider Henry Kelsey, which is also very vigorous. I had mine on an arbor originally, though it isn't now. As you can see from the following photo, it blooms profusely in June and will also produce a few more flowers later in the summer.

My favorite climber is Don Juan, but it is so tender that I have to keep in a very protected spot on the west wall of the house, between a porch on the north and a juniper on the south.

How thick is the arbor? If its one of those cheapie scrawny ones it will never last through the weather, let alone a climbing rose. If its a strong, made from thick posts, like 4 x 4's that will be fine.The canes on a climbing rose don't get thick like a tree trunk or anything, although they do get some size to them, but nothing to worry about.

Maybe you are thinking multiflora rose? Not native, actually I think it's considered invasive in Pa. I don't think any of the native roses are climbers.

I have William Baffin started, but it's still a year or two off from being anything impressive. I might just keep it as a large shrub though since I haven't gotten up to trellises yet.... still working on beds and the basics (I've been known to suffer from severe laziness here and there, and that doesn't get trellises built!)

I'm with Kato_b on the roses.They are growing in the wild but are not native.Not originally. I would go for a tamer variety. There are many. If you put the wild ones in you'll just end up with a big thicket of jaggy yuk. They don't bloom worth a crap anyway.

New Dawn is incredibly healthy and floriferous for me, but it is really a maneating rose. Huge. I keep having to do battle with it-- it's trying to eat my family. Great rose, but don't do what I did and plant it along a narrow much used walkway.

Cold hardiness is important because many modern roses die back to the ground in PA. Starting over from the ground each year works for a bush, but the whole effect of a climber is lost if it only recovers to four or five feet. William Baffin is a good example of a rose bred to survive the cold. I believe New Dawn is another tough climber. Remember, just because your local nursery sells a rose does not mean it is hardy locally.

Disease resistance is also critical. PA is home to many fungal diseases which can ruin the appearance of your rose. It is harder to spray an 8' high rose.

Rebloom may be important to you. Many of the tough climbers do not. Some produce a few later blooms.

Fragrance is rare in hardy climbers.

Very few climbers meet all of these criterion.

I have successfully grown Westerland. It thrives here just south of Allentown. It may suffer winter dieback in the coldest areas of PA. It is only "somewhat" resistant to black spot and requires 3-5 fungicide applications per season. Westerland repeats well and is fragrant.

I have grown William baffin and Z. Drouhin and loved them both. At my current house I have "John Cabot", which I had for the first full year last year. This year it is set to make a nice show of blooms. I have trained it along the horizontal boards of a fence, and it is sending up vertical shoots all along the outstretched canes. It is extremely thorny though!

I have moved and do not have pics of the old house. But America Climbing Rose. It was fragrant and extremely low maintenance. I o not like to baby my hardy plants.

I posted on the Rose forum for some help awhile back. There are more people in warmer zones on that forum and I did not get much in suggestions except to go and find a Rose group in my area.

I know you asked about roses but if you want a companion plant to climb and fragrance to supplement your climbing rose I cannot say enough good about Clematis triternata Rubromarginata. Long bloomer. Blooms most of the summer until Fall. It bloomed when my roses take a rest when the summer gets really hot. The fragrance can be smelled across the yard.